Archeologists can determine the age of artifacts made of wood or bone by measuring the amount of the radioactive isotope 14C present in the object. The amount of isotope decreases in a first-order process. If 15.5% of the original amount of 14C is present in a wooden tool at the time of analysis, what is the age of the tool? The half-life of 14C is 5730 yr.

Hbr dissociates to form h+ and br-ca(oh)2 dissociates to form ca2+ and 2oh-the h+ and oh- react to form waterassuming the reactants are dissolved in water, the net reaction is h+ + oh- —> h2oif you’re asked to show all components of the reaction, the complete reaction is 2hbr + ca(oh)2 —> cabr2 + 2h2o

Product should she record in last row of the table

rosa was looking for patterns to predict the products of chemical reactions. she recorded three similar decomposition reactions in the table.she should record 2licl + 3o2.

in the last row of the table. it is the thermal decomposition of chlorate lithium, hence, she should record these products as: lithium chloride ( 2licl ) and oxygen ( 3o2 )   2 > 2 licl + 3o2.

Polyethylene is a strong synthetic polymer that can be used to make toys and bottles. this makes plastics which are important also to people but sometimes it lead to harmful environmental effects such as global warming if these plastics are burned.

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